Muro 128 (sodium chloride hypertonicity ophthalmic ointment, 5%) offers effective relief when you suffer from corneal edema (swelling of the cornea). Muro 128 ointment can be applied every 3 to 4 hours, or as directed by a doctor. This product contains no mercurial compounds such as Thimerosal. The ointment is available without prescription but should only be used upon recommendation by an eye care professional.